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  1. Home
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Browsing by Author "Maina, Esther N."

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    Advances in green nanobiotechnology: Data for synthesis and characterization of silver nanoparticles from ethanolic extracts of fruits and leaves of Annona muricata
    (Data in brief, 2019) Gavamukulya, Yahaya; El-Shemy, Hany A.; Meroka, Amos M.; Madivoli, Edwin S.; Maina, Esther N.; Wamunyokoli, Fred; Magoma, Gabriel
    In this data article, data obtained from an efficient, eco-friendly and low-cost method for the synthesis and recovery of Silver nanoparticles (AgNPs) using ethanolic extracts of Annona muricata fruits and leaves as reducing, stabilizing and capping agents has been reported. 99.7% pure silver nitrate was used as the inorganic ion source. The data was obtained using different spectroscopic and microscopic techniques. The data is presented in form of images, Microsoft excel sheets, graphs,.raw files,.dpt files, PDF files, among others. Methods of analysis and interpretation of the data have also been presented. The data can be most useful to researchers, research students, industrialists and academicians to acquire knowledge on the green synthesis of AgNPs and related
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    Annona muricata silver nanoparticles exhibit strong anticancer activities against cervical and prostate adenocarcinomas through regulation of CASP9 and the CXCL1/CXCR2 genes axis
    (Tumor Biology, 2021) Gavamukulya, Yahaya; Maina, Esther N.; El-Shemy, Hany A.; Meroka, Amos M.; Kangogo, Geoffrey K.; Magoma, Gabriel; Wamunyokoli, Fred
    Green synthesized nanoparticles have been earmarked for use in nanomedicine including for the development of better anticancer drugs. OBJECTIVE: The aim of this study was to undertake biochemical evaluation of anticancer activities of green synthesized silver nanoparticles (AgNPs) from ethanolic extracts of fruits (AgNPs-F) and leaves (AgNPs-L) of Annona muricata. METHODS:Previously synthesized silver nanoparticles were used for the study. The effects of the AgNPs and 5-Fluorouracil were studied on PC3, HeLa and PNT1A cells. The resazurin, migration and colonogenic assays as well as qRT-PCR were employed. RESULTS: The AgNPs-F displayed significant antiproliferative effects against HeLa cells with an IC50 of 38.58 g/ml and PC3 cells with an IC50 of 48.17 g/ml but selectively spared normal PNT1A cells (selectivity index of 7.8), in comparison with first line drug 5FU and AgNPs-L whose selectivity index were 3.56 and 2.26 respectively. The migration assay revealed potential inhibition of the metastatic activity of the cells by the AgNPs-F while the colonogenic assay indicated the permanent effect of the AgNPs-F on the cancer cells yet being reversible on the normal cells in contrast with 5FU and AgNPs-L. CASP9 was significantly over expressed in all HeLa cells treated with the AgNPs-F (1.53-fold), AgNPs-L (1.52-fold) and 5FU (4.30-fold). CXCL1 was under expressed in HeLa cells treated with AgNPs-F (0.69-fold) and AgNPs-L (0.58-fold) and over expressed in cells treated with 5FU (4.95-fold), but the difference was not statistically significant. CXCR2 was significantly over expressed in HeLa cells treated with 5FU (8.66-fold) and AgNPs-F (1.12-fold) but under expressed in cells treated with AgNPs-L (0.76-fold). CONCLUSIONS: Here we show that biosynthesized AgNPs especially AgNPs-F can be used in the development of novel and better anticancer drugs. The mechanism of action of the AgNPs involves activation of the intrinsic apoptosis pathway through upregulation of CASP9 and concerted down regulation of the CXCL1/ CXCR2 gene axis.
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    Antiproliferative Activity, c-Myc and FGFR1 Gene Expression Profiles and Safety of Annona muricata Fruit Extract on Rhabdomyosarcoma and BALB/c Mice
    (Journal of Complementary and Alternative Medical Research, 2021) Chikwana, Naomi; Maina, Esther N.; Gavamukulya, Yahaya; Bulimo, Wallace; Wamunyokoli, Fred
    Rhabdomyosarcoma is an aggressive solid tumour of skeletal muscles origin whose current treatment is associated with high expenses, severe side effects, drug resistance and tumour regrowth. There is a need to develop safer and more effective chemotherapeutic agents. Annona muricata is one of the widely used plants in treating various diseases due to its reported effectiveness. However, there is a dearth of scientific information regarding the efficacy of Annona muricata on rhabdomyosarcoma and its safety. This study aimed to evaluate the effects of Annona muricata ethanolic fruit extract on the antiproliferative activity and gene expression in RD cell line, including its biosafety in BALB/c mice. Materials and Methods: The resazurin metabolic assay was used to assess the antiproliferative and cytotoxic activities of Annona muricata ethanolic fruit extract on RD and Vero cells. Quantitative real-time polymerase chain reaction was used to assess the gene expression profiles on c-Myc and FGFR1 genes. To evaluate the safety of the Annona muricata ethanolic fruit extract, an acute oral toxicity study was conducted on BALB/c mice. Results: Annona muricata ethanolic fruit extract significantly inhibited the growth of RD cells in a concentration and time-dependent manner while being highly selective on the Vero cells (selectivity index of 6.10 at 72h) compared to a reference cancer drug, doxorubicin (Selectivity index of 1.38 at 72hr). The c-Myc and FGFR1 genes were under expressed in RD cells treated with Annona muricata ethanolic fruit extract with (3.4 and 6.1 fold), respectively, compared to untreated cells. Acute oral toxicity studies revealed no significant difference (p ≥ 0.05) between the treated mice and the control group, indicating the safety of the fruit extract. Conclusion: Annona muricata ethanolic fruit extract can serve as effective and safe anticancer agents against rhabdomyosarcoma and further develop into standard drugs. Non-human primate studies need to be undertaken to step towards the clinical utilization of the Annona muricata ethanolic fruit extract in the management of rhabdomyosarcoma.
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    Dermaseptin B2’s Anti-Proliferative Activity and down Regulation of Anti-Proliferative, Angiogenic and Metastatic Genes in Rhabdomyosarcoma RD Cells in Vitro
    (Advances in Bioscience and Biotechnology, 2021) Abdille, Ahmed A.; Kimani, Josephine; Wamunyokoli, Fred; Bulimo, Wallace; Gavamukulya, Yahaya; Maina, Esther N.
    Rhabdomyosarcoma (RMS) is the most prevalent soft tissue sarcoma in children, representing approximately 50% of pediatric sarcomas and can develop in any part of the body though more frequently at the extremities. Aim: Evaluating the in vitro anti-proliferative activity of Dermaseptin B2 on Rhabdomyosarcoma RD (CCL-136TM) cells and its effect on the expression of MYC, FGFR1, NOTCH1, and CXCR7 genes involve in processes including proliferation, angiogenesis and metastasis. Methods: RD cells were grown in Dulbecco’s Modified Eagle’s Medium supplemented with 10% Fetal Bovine Serum. Exponentially growing cells were treated with Dermaseptin B2 and Antiproliferative activity was assayed using the resazurin and migration assays at three time-points. In order to determine the gene expression profiles of MYC, NOTCH1, FGFR1 and CXCR7, total RNA was extracted from the cells and q-RT-PCR was performed with β-Actin as reference gene. Results: Dermaseptin B2 inhibited the proliferation of RD cells in a time and concentration dependent manner as with IC50 values of 7.679 μM, 7.235 μM, 5.993 μM. The 2-dimentional wound healing assay showed inhibition of migration and motility of the RD cells at time-points of 6, 24, 48 and 72-hours with the greatest inhibition observed at 72-hours. Dermaseptin B2 downregulated the target MYC (fc; 1.5013, 1.5185, 2.4144), CXCR7 (fc; 2.8818, 4.4430, 3.9924), FGFR1 (fc; 2.3515, 2.0809, 2.2543), NOTCH1 (fc; 2.4667, 4.6274, 4.3352) genes for the three-time points respectively. NOTCH1 and CXCR7 showed higher fold changes with respect to β-Actin than MYC and FGFR1. Conclusion: The results of this study indicate that Dermaseptin B2 is a target molecule for signaling pathways including PI3K/AKT, RTK and NOTCH pathways that could affect the transcription of these genes and overall inhibition of cancer progression. Further studies are needed to give a better understanding of the detailed mechanisms of action as well as the effects of the Dermaseptin B2 peptide in vivo.
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    Green Synthesis and Characterization of Highly Stable Silver Nanoparticles from Ethanolic Extracts of Fruits of Annona muricata
    (Journal of Inorganic and Organometallic Polymers and Materials, 2020) Gavamukulya, Yahaya; Maina, Esther N.; Meroka, Amos M.; Madivoli, Edwin S.; El‑Shemy, Hany A.; Wamunyokoli, Fred; Magoma, Gabriel
    Green synthesis of nanoparticles from plant materials opens a new scope in nanobiotechnology and discourages the use of expensive toxic chemicals. The aim of this study was to develop and optimize a method for the synthesis of Silver Nanoparticles (AgNPs) from ethanolic extracts of fruits of Annona muricata as well as to characterize the green synthesized AgNPs. AgNPs were synthesized via AgNO3 solution. The AgNPs were characterized using spectroscopy and microscopy techniques. The formed AgNPs had an absorption maximum of 427 nm and were stable under different temperature, pH and storage conditions. Fourier Transform Infrared Resorption spectroscopy revealed the functional groups responsible for the synthesis and stabilization of the AgNPs. Scanning Electron Microscopy analysis revealed a spherical nature of the AgNPs. Energy Dispersive X-Ray spectroscopy showed presence of Ag, Cl, Ca, and Si with Ag having the highest composition at 80%. X-ray diffraction and dynamic light scattering revealed a crystalline nature of AgNPs with an average size of 60.12 nm and a polydispersity index of 0.1235 respectively. Transmission Electron Microscopy analysis further confirmed the crystalline and spherical nature of the AgNPs. In this article, an efficient, eco-friendly and low-cost method for the synthesis and recovery of stable AgNPs using ethanolic extracts of Annona muricata fruits as both reducing and capping agents has been reported. The synthesized AgNPs could have many biomedical and clinical applications.
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    In search of new anticancer drugs: Data for cytotoxic activities of green synthesized silver nanoparticles from ethanolic extracts of fruits and leaves of Annona muricata and 5- Fluorouracil against HeLa, PC3 and PNT1A cell lines
    (Data in brief, 2019) Gavamukulya, Yahaya; Maina, Esther N.; Meroka, Amos M.; El-Shemy, Hany A.; Magoma, Gabriel; Wamunyokoli, Fred
    In this article, we present data on the anticancer activities of green synthesized silver nanoparticles (AgNPs) from ethanolic extracts of fruits (AgNPs-F) and leaves (AgNPs-L) of Annona muricata and standard anticancer drug 5-Fluorouracil (5-FU) on two cancer cell lines, i.e. cervical adenocarcinoma (HeLa cells) and prostate adenocarcinoma (PC3 cells) as well as on an immortalized normal prostate cell line, PNT1A. The cytotoxicity on the cells was determined by measuring the absorbance signal of resazurin dye. It has long been known that metabolically active cells change the resazurin from blue (oxidized) to red (reduced) forms, corresponding to the absorbance signals at a wavelength of 570nm (A570) and 600nm (A600) respectively, from which therefore the effects of any treatments on percentage cell viability/death can be elucidated. The raw data values of the treatments against the HeLa, PC3 and PNT1A cells are shown in the different Tables. Examples of how the data can be analyzed have been illustrated using different growth inhibition curves. The data can be used by academics, students, and researchers working on development of anticancer drugs.
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    Liquid Chromatography Single Quadrupole Mass Spectrometry (LC/SQ MS) Analysis Reveals Presence of Novel Antineoplastic Metabolites in Ethanolic Extracts of Fruits and Leaves of Annona muricata
    (Pharmacognosy Journal, 2019) Gavamukulya, Yahaya; Maina, Esther N.; Meroka, Amos M.; Madivoli, Edwin S.; El-Shemy, Hany A.; Magoma, Gabriel; Wamunyokoli, Fred
    Annona muricata, a tropical plant species belonging to family Annonaceae is one of the most used plants in folk medicine because of its many medicinal uses. Despite its wide usage, there is still need to continue scientifically evaluating its medicinal properties in order to avoid any adverse effects. Elucidating the detailed chemical composition of this plant is a significant step towards this evaluation. Objective: The aim of this study was to conduct LC MS analysis on the ethanolic extracts of fruits and leaves of Annona muricata for detection of novel metabolites. Materials and Methods: Leaves and fruits of Annona muricata were collected from Eastern Uganda during the month January 2018. Extraction was conducted using the tissue homogenization method and the extracts were analyzed on an LC/SQ MS detection system. The results were obtained by analyzing the MS spectra using the retentions time and fragmentation patterns on the NIST Library. Results: The study revealed that the fruits extracts contain 1,3-Dimethylthiourea and (4-chlorophenyl)-[4-(3-chlorophenyl)-2-[(Z)-3-(dimethylamino) prop-1-enyl]quinolin-6-yl]-(3-methylimidazol-4-yl)methanol, which are reported antioxidant and antineoplastic agents. The leaves contained 2,4,6-Tribromoaniline another antioxidant and antineoplastic agent, while compound (dichlorozirconium(2+);dimethyl-bis(2-methyl-4- phenylinden-1-id-1-yl)silane was found in both extracts of fruits and leaves. Conclusion: The current study suggests that ethanolic extracts of fruits and leaves of Annona muricata contain compounds which are potent antioxidant, antineoplastic and therapeutic agents for various conditions and paves the way for the development of several treatment regimens from these plant parts. Finally, the compounds reported in this study have been identified for the first time as being found in Annona muricata.
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    Sub-acute and sub-chronic toxicity assessment of the antimicrobial peptide Dermaseptin B2 on biochemical, haematological and histopathological parameters in BALB/c mice and Albino Wistar rats
    (Heliyon, 2022) Abdille, Ahmed A.; Kitimu, Shedrack Reuben; Ndubi, Mark M.; Kimani, Josephine; Maina, Esther N.; Bulimo, Wallace; Gavamukulya, Yahaya; Wamunyokoli, Fred
    Dermaseptins (Drs) are peptides found in the skin secretions of a variety of Hylid frogs, particularly those belonging to the Agalychnis and Phyllomedusa families. Dermaseptin B2 (Drs B2), an amphipathic, α-helical polypeptide was reported as the most active of the Dermaseptin B family. We have previously shown that Drs B2 has strong anti-proliferative activities against RD cells in vitro and thus required further evaluations for future medical applications. Aim: The aim the study was to evaluate the 14-day sub-acute and 90-day sub-chronic toxicities Drs B2 in vivo. Materials and Methods: BALB/c mice were treated with increasing concentrations of 5–25 mg/kg of Drs B2. Rats were treated with 2, 4 and 10-fold concentrations of the calculated LD50 of Drs B2 following OECD recommendations. At the end of the experimentation periods, the animals were sacrificed and dissected to collect blood and selected organs for analysis of any effects caused by Drs B2 treatment on the biochemical, haematological, and histological parameters. Results: The 14-day sub-acute toxicity tests did not cause significant alteration in the biochemical, hematological and histological parameters. The 90-day sub-chronic toxicity study showed lower ALT and AST than control at doses 1.9 mg/kg and 4.6 mg/kg, respectively. Their haematology results also showed higher platelet count than the controls but the differences were not statistically significant. Histological analysis showed increased megakaryocytes in the spleen for both the mice and the rats. Conclusion: The results of this study indicate that short term treatment of Drs B2 could be safe to the animals, however, long-term treatment can have mild effects on the liver parameters and cause an inflammatory response in the spleen.
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    Synthesis and Characterization of Silver Nanoparticles from Ethanolic Extracts of Leaves of Annona muricata: A Green Nanobiotechnology Approach
    (Biotechnology Journal International, 2019) Gavamukulya, Yahaya; Maina, Esther N.; Wamunyokoli, Fred; Meroka, Amos M.; Madivoli, Edwin S.; El-Shemy, Hany A.; Magoma, Gabriel
    The biological green synthesis of nanoparticles via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. Annona muricata, a tropical plant belonging to family Annonaceae is one of the most used plants in folk medicine because of its many medicinal uses and therefore presents a strong candidate for use in green synthesis. Aims: The aim of this study was to optimize a method for the synthesis of Silver Nanoparticles (AgNPs) from ethanolic extracts of leaves of Annona muricata as well as to characterize the green synthesized AgNPs. Methodology: AgNPs were synthesized from Annona muricata leaves using AgNO3 solution. The AgNPs were characterized using spectroscopy and microscopy techniques. Results: The formed AgNPs had an absorption maximum at 429 nm using UV–Visible spectroscopy and were stable under different pH, temperature, and storage conditions. Fourier transform infrared analysis revealed the different functional groups responsible for the synthesis and stabilization of the AgNPs. Scanning electron microscopy analysis revealed a spherical nature of the synthesized AgNPs. Energy dispersive x-ray spectroscopy analysis showed presence of Ag, O, and Cl with Ag having the highest composition at 60%. X-Ray Diffraction and Dynamic Light Scattering revealed a crystalline nature of AgNPs with an average size of 87.36 nm and a polydispersity index of 0.16 respectively. Transmission Electron Microscopy analysis further confirmed the crystalline and spherical nature of the AgNPs. Conclusion: In this article, an efficient, eco-friendly and low-cost method for the synthesis and recovery of stable AgNPs using Annona muricata leaves ethanolic extracts as both a reducing and capping agent has been reported for the first time. The synthesized AgNPs could be promising candidates for many biomedical, clinical, engineering, and polymer applications.
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    The Potential of Differentiation Related Gene 1 DRG1) as a Biomarker for Metastasis of Estrogen Receptor Positive Breast Cancer
    (Journal of Advances in Medicine and Medical Research, 2021) Bor, Hillary; Maina, Esther N.; Nyambega, Benson; Tushar Patel, Kirtika; Ochieng’ Olwal, Charles; Nalyanya, Walter; Gavamukulya, Yahaya
    Breast cancer is major burden worldwide and the majority of breast cancers express estrogen receptors (ER) suggesting a high dependence on estrogen hormone. Age is among the major determinants of breast cancer development, however, although Western Kenya is one of the areas with high breast cancer cases, age distribution of ER-positive breast cancer in the sub-region remains largely undocumented. Differentiation-related gene-1 (DRG1) is a metastasis suppressor and thus a potential biomarker for predicting level of metastasis but its potential application in assessing extent of metastasis of ER positive breast cancer has not been fully explored. This study therefore investigated the age distribution and the potential of expression of DRG1 in assessing metastasis of ER positive breast cancer. Materials and Methods: Breast cancer tumour blocks archived in safe cabins in the histology laboratory section, Moi Teaching and Referral hospital, Eldoret, Kenya were used. Clinico-pathological parameters such as histology grade, tumor size, which are associated with metastatic cancer, were assessed using the archived clinico-pathological reports and/or histological analysis of the tumour blocks. Expression of DRG1 and Ki-67 proteins were determined using immunohistochemistry. Results: ER positive breast cancer was predominant among women aged 40 and 50 years. No association was observed between immunohistochemical expression of DRG1 and parameters such as histology grade, tumor size or expression of Ki-67 protein expressed DRG1 (p > 0.05). Conclusion: The findings suggest that expression of DRG1 protein is not associated with parameters that indicate breast cancer metastasis. Thus, DRG1 expression is not a potential biomarker candidate for ER positive breast cancer metastasis. However, since the small sample size was used, further research using larger prospective study is necessary to support the present findings.

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